This invention relates to integrated circuit sockets and, more particularly, to such sockets which are used with integrated logic circuits that require specific termination circuits.
Certain types of digital logic integrated circuits require specific termination circuits for satisfactory operation. For example, emitter coupled logic (ECL) and transistor transistor logic (TTL) drivers are typically terminated by a resistor or resistor network which is connected to a predetermined voltage level. Other types of termination are well known. For example, with parallel termination, the integrated circuit logic gate is connected to a junction point between two series connected resistors. With diode termination, a pair of inverse parallel diodes serve as the terminating network. In typical logic circuit board layouts, the required terminating components are provided by single in-line package resistor packs, dual in-line package resistor packs, or discrete resistors or diodes. In each case, significant amounts of printed circuit board space are required. For example, since every ECL logic gate output needs to be terminated, a large quantity of terminating components is required.
It is therefore desirable to provide an integrated circuit socket which eliminates the need for separate space consuming, circuit termination elements.